1. Field of the Invention
The present invention relates to a controller operation verification system, an image processing apparatus, a controller operation verification apparatus, an image data output control method, an image data restoration method, a storage medium, and a program, and more particularly, to a controller operation verification system which verifies an operation of a controller constituting a printer in cooperation with an engine for outputting image data to a medium such as a paper or the like and is appropriately applied to a printer emulator supporting development of the printer, an image processing apparatus to which this system is applicable, a controller operation verification apparatus, an image data output control method, an image data restoration method, a storage medium, and a program.
2. Related Background Art
Conventionally, as shown in, e.g., FIG. 15, a printer 1500 which acts as an image output apparatus is connected to a host computer 1510 which includes a printer driver 1511, through a network, a USB (Universal Serial Bus) interface or the like. The printer 1500 includes a controller unit 1501 which converts intermediate output data generated from a print origin data by an apparatus such as the host computer 1510 or the like into output image data suitable for an output operation, and an engine unit 1502 which obtains the output image data output from the controller unit 1501 and outputs the data to form an image on a medium such as a paper or the like.
When an image is output by a laser beam printer which acts as an example of the printer, the intermediate output data suitable for the controller unit 1501 of the printer 1500 is generated by equipment such as the host computer 1510 or the like in accordance with software generally called the printer driver 1511. Then, the intermediate output image data is input to the controller unit 1501 of the printer 1500 through a network line such
was a parallel line, a USB, Ethernet™ or the like. In the controller unit 1501, the intermediate output data is converted into the output image data suitable for the engine unit 1502, and the converted data is output as a video signal to the engine unit 1502 in sync with an image transfer permission signal supplied from the engine unit 1502. Then, in the engine unit 1502, an electrophotographic process for the video signal is controlled and driven, whereby the input video signal is output as the image on the medium such as the paper or the like. Here, it should be noted that output timing of the image transfer permission signal from the engine unit 1502 is determined on the basis of a paper transportation status, an electrophotographic process status and the like. Moreover, a general color conversion process or the like is performed by either the printer driver 1511 or the controller unit 1501.
Next, the above conversion process to convert the intermediate output data into the output image data suitable for the engine unit 1502 will be explained in detail. Japanese Patent Application Laid-Open No. 62-188552 discloses a method of achieving a gradation process suitable for a halftone output characteristic of an image forming apparatus acting as an output apparatus by converting halftone-processed digital image data into an analog signal according to pulse-width modulation. In recent years, such a process to convert the halftone data into the analog signal is widely adopted as a means for obtaining a high-definition image at high speed, according as printers of high image quality are being developed.
Incidentally, the controller unit 1501 and the engine unit 1502 are connected with each other by a communication path called a video interface. This video interface includes a video signal for transferring the above output image data, a control signal for controlling timing of the video signal and the like, a command signal for causing the controller unit 1501 to issue instructions to the engine unit 1502, a status signal for causing the engine unit 1502 to notify the controller unit 1501 of the status of the engine unit itself, an interrupt signal, and the like.
Here, the above paper transportation status indicates the status of paper within the engine unit while paper feeding, printing, paper discharging or the like is being performed, and the above electrophotographic process status indicates an idle status, an initialization status, an under-postprocess status or the like. The engine unit 1502 is not always in the printable status, that is, the engine unit 1502 outputs the image transfer permission signal to the controller unit 1501 only when it is in the printable status. The controller unit 1501 and the engine unit 1502 operate closely and cooperatively by using the control signal, the command signal and the status signal.
In conventional printer development and operation verification processes, the intermediate output data generated by a host computer is transmitted to the controller unit to actually operate the engine unit, whereby an output image (printed material) is obtained. Then, the operation of the printer is evaluated and verified by measuring the output time necessary to obtain the output image and directly and visually observing the output image and the obtained statuses. Moreover, the processes of generating the intermediate output data, outputting the data from the engine unit, measuring the output time, evaluating the output image, and verifying communication reasonability are repeatedly performed.
However, in the conventional technique that the output image is obtained to evaluate and verify it by actually operating the printer, the evaluation and verification can only be performed after the development of both the controller unit and the engine unit progresses enough and it arrives at the stage where both the controller unit and the engine unit actually operate. Under the circumstances, it is very difficult to shorten a development term and achieve parallel developments of these units. Moreover, since an amount of the printed materials to be used to evaluate the image and measure a print time becomes huge, there is a problem that, to prepare the printed materials, a long time is consumed and a large amount of consumable supplies and materials such as toner, print papers and the like are necessary.
To solve the above problem, Japanese Patent Application No. 2001-110529 which was filed previous to the present application by the applicant same as the assignee of the present application proposes an image processing apparatus which receives a video signal output from a controller unit and then visualizes the received signal as an image on a display such as a CRT or the like. That is, by using this image processing apparatus, in the printer development process, the video signal output from the controller unit can be visualized without using an engine unit to verify an output image, whereby consumable supplies and materials such as toner, print papers and the like can be saved, and various tests can be automatized. Moreover, since a controller operation can be verified without using the engine unit, development of the engine unit and development of the controller unit can be achieved separately in parallel, whereby development efficiency can be greatly improved.
However, there are following problems in the above previous Japanese application. That is, in the above image processing apparatus, the video signal output from the controller unit is usually converted into the analog signal according to the pulse-width modulation, whereby it is necessary to again convert the analog signal into the halftone digital image data so as to confirm the content of the analog signal in the former halftone representation. Otherwise, it is necessary to provide a means for externally capturing the signal before the digital data is converted into the analog signal and then sending the captured signal (digital data) to the image processing apparatus. In the former case, since a conversion error occurs when the analog signal is converted into the digital data, inconvenience occurs in the detailed verification operation for the output data. On the other hand, in the latter case, a dedicated signal line, a driver circuit and the like are necessary to send the multivalued halftone data, costs for the controller unit increase.